Reinforcing-bar for concrete structures.



No. 870,129. 7 PATENTED NOV. 5, 1907. A. PRIDDLE.

REINFORGING BAR FOR'CONGRETE STRUCTURES. APPLICATION FILED SEPT.20,1906.

TIE-- E attoznaa o -ARTHUR PRIDDLE, OF SAN FRANCISCO, CALIFORNIA.

REINFORGING-BAR FOR CONCRETE STRUCTURES.

Specification of Letters Patent.

Patented Nov. 5, 1907.

Application filed September 20. 1906, Serial No. 335391.

To all whom it may concern:-

Be it known that I, ARTHUR PRIDDLE, a citizen of the United States, residing at San Francisco, in the county of San Francisco and State of California, have invented certain new and useful Improvements in Reinforcing-Bars for Concrete Structures, and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in devices for reinforcing concrete structures, and it consists of the novel construction, combination and arrangement of parts hereinafter described and claimed.

The object of the invention is to provide a simple and inexpensive tension bar or element which may be embedded or anchored in a concrete structure of any description to effectively strengthen and reinforce the same.

The above and other objects, which will appear as the nature of theinvention is better understood, are accomplished by the construction herein described and illustrated by the accompanying drawing, in which,

Figure 1 is a side elevation of a portion of one form of the improved reinforcing bar or member; Fig. 2 is a sectional perspective view. of the same; Fig. 3 is a view similar to Fig. 1, of a slightly modified form of the invention; and Fig. 4 is a transverse sectional view taken on a plane indicated by the line 44 in F ig. 3.

In the practice of the invention, I preferably employ a flat metallic bar 1 of rectangular form in cross section and by suitable means slit the same longitudinally at points suitably distant apart. I then stamp or bond by suitable means, the edges of the slits or openings 2 outwardly to form right angular anchoring flanges or ribs 3. These flanges or ribs 3 may be bent outwardly in either direction at right angles to the plane of the bar and they are preferably curved and tapered longitudinally so as to leave the slit or opening 2 of substantially elliptical form. The slits or openings 2 may be of any desired size and arranged at any desired distance apart and they do not in any way weaken the bar since its sectional area is not reduced. On the contrary, they add strength and rigidity to the bar because they form arches, two of which are formed by the elliptical curvature that corresponds with the walls of the opening, which will strengthen the bar in the plane of its width, or widest section, and the and the flanges 3 may be cut and stamped in the flat bar 1 without heating the same but in some cases when the bar is very heavy and of other forms than that shown it may be necessary to heat the same to permit the slits or openings to be formed therein. If desired, the 1 bar 1 may be twisted spirally at suitable intervals, as shown in Figs. 3 and 4. The twist helps the bar and concrete to mutually anchor each other .in the structure, thereby strengthening the latter to a greater extent than would a straight bar. In other words, the changing shape of the twist bar serves to conserve the strength of the concrete and does not tend to weaken it as does a straight or flat bar when set upon its edge, the fiat bar in such case forms in a sense a cutting edge when under severe strain, and hence tends to weaken the concrete. This objection is overcome in the twist bar, as will be understood.-

In use, the bar or member is embedded in concrete structures, such as floors, arches, beams, girders,

foundations, walls, columns, piers and similar structures of concrete or.other plastic material. The bar may be arranged in concrete in any shape, singly or compound, at any angle, and at any suitable distances apart, and if desired, the bars may be laid at right angles in the structure and tied together with suitable fasteners; or the bars may be woven together, forming a fabric where the necessity requires the placing of considerable material of this nature in the structure. The weaving may be accomplished by stringing the bars through the perforations and tying'them in as desired. i

From the foregoing description, taken in connection of the advantages of this invention, as defined by the.

appended claims.

Having described my invention, what I claim as new and desire to secure by Letters-Patent is,-

1. A reinforcing element for concrete structures, comprising a flat metallic liar having slits formed longitudinally therein, and having the portions of the bar adjacent to said slits bent laterally in opposite directions at right angles to the plane of the bar, whereby flanged elliptical or bent portion is in the form oi! an arch lengthwise of the bar, and the outer edge is in the form of an arch at I right angles to the plane oi. the bar.

.2. A flat, spiral, tv'visted reinforcing bar having an opening extending longitudinally thereof, said opening having oppositely curved sides, each formed by a longitudlnally-curved lip projecting laterally from the general plane of that portion or the bar in which said opening is located, said lips being broadened at their centers and 10 narrowed toward their ends, and respectively extending from opposite sides of -the bur.

In testlmony whereot I have hereunto set my hand in presence of two subscribing witnesses. v

ARTHUR PRlDDLE.

Witnesses:

SAML. H. Hnmnmnsn, Josnrn ALLEN RICHMOND. 

